Buildings, such as for example residential buildings, are typically covered by sloping roof planes. The interior portion of the building located directly below the sloping roof planes forms a space called an attic. If unventilated or under-ventilated, condensation can form on the interior surfaces within the attic. The condensation can cause damage to various building components within the attic, such as for example insulation, as well as potentially causing damage to the building structure of the attic. In addition, unventilated or under-ventilated spaces are known to cause ice blockages (“ice dams”) on the sloping roof planes. The ice blockages can cause water to damage portions of the various building components forming the roof and the attic.
Accordingly it is known to ventilate attics, thereby helping to prevent the formation of condensation. Some buildings are formed with structures and mechanisms that facilitate attic ventilation. The structures and mechanisms can operate in active or passive manners. An example of a structure configured to actively facilitate attic ventilation is an attic fan. An attic fan can be positioned at one end of the attic, typically adjacent an attic gable vent, or positioned adjacent a roof vent. The attic fan is configured to exhaust air within the attic and replace the exhausted air with fresh air.
Examples of structures configured to passively facilitate attic ventilation include ridge vents and soffit vents. Ridge vents are structures positioned at the roof ridge, which is the intersection of the uppermost sloping roof planes. In some cases, the ridge vents are designed to cooperate with the soffit vents, positioned near the gutters, to allow a flow of air to enter the soffit vents, travel through a space between adjoining roof rafters to the attic, travel through the attic and exit through the ridge vents.
U.S. Pat. No. 4,962,699, which is incorporated herein by reference in its entirety, discloses a ridge vent made from randomly convoluted filaments. Prior art FIGS. 1 and 2 are taken from U.S. Pat. No. 4,962,699. U.S. Pat. No. 4,962,699 is incorporated by reference in its entirety.
FIGS. 1 and 2 illustrate a typical roof construction. The structural members of the roof may comprise a plurality of rafters 10, conventionally supported at their lower ends by the front and rear walls of the building. The upper ends of the rafters 10 meet at, and are attached to, a ridge pole 12, which extends between the end walls 14 of the building. Sub-roofing 15, typically comprising plywood panels, is secured to the rafters 10 and extends to the end walls 14. Conventional shingles 16 may be nailed to the sub-roofing 14 to finish the sloping portions of the roof in accordance with accepted construction practice. Conventional cap shingles 18 may then be employed in over lapping fashion to cover the peak of the roof, above the ridge pole 12. A vent 20 made from randomly convoluted filaments is interposed between the cap shingles 18 and the underlying, compositely formed portions of the roof.
A slot 22 is provided along the length of the peak of the roof to provide a passageway for venting air from the underlying attic area. The ends of the slot are spaced from the opposite ends of peak, as seen in FIG. 2. The vent 20 comprises a sheet material layer 24 and a matrix 26 of randomly convoluted filaments. The sheet material 24 serves several purposes. One characteristic is that the sheet material layer is permeable, to permit the free flow of air in venting the attic area of the roof. Another function of the sheet material is to provide a barrier protecting the attic area from the entry of both insects and water and/or snow.
As will be seen from FIG. 1, the sheet material layer 24 overlies the slot 22, thus providing a primary barrier for preventing entry of insects, and other foreign matter, into the attic area. It will further be seen that the sheet material layer 24 is wrapped around the side surfaces of the matrix 26 of randomly convoluted filaments. The sheet material 24 is heat bonded or laminated and/or bonded by a layer of adhesive to a bottom surface of the matrix of randomly convoluted filaments. Further, the sheet material layer 24 is also wrapped around the end surfaces of the resilient matrix 26 (See FIG. 2). There is thus provided a barrier which prevents the intrusion of insects into the matrix 26.
While the sheet material layer is permeable to air, as is necessary for its venting function, preferably, it is a barrier to liquid flow. This function is required, for example, in the event of driving rain, to prevent water from entering the attic area. The feature of wrapping the sheet material layer around the side and end edges of the resilient matrix 26 provides this water barrier function. It is further preferred that the sheet material layer 24 be non-wicking, and preferably hydrophobic. In another exemplary embodiment, the sheet material layer 24 is wicking and hydrophilic. Once the wicking and hydrophilic sheet material layer 24 is saturated, the sheet material layer becomes a barrier to liquid flow.
The several functions and characteristics of the layer 24 are preferably provided by a non-woven polyester fiber, filter fabric. In an exemplary embodiment, the sheet material layer 24 has a thickness of approximately 0.030 inch and has an equivalent opening size of 150 microns. In an exemplary embodiment, the sheet material layer 24 has a net free volume of greater than 80%, such as a net free volume of greater than or equal to 85%. A non-woven fabric may be characterized by being constituted with a liquid, acrylic binder, which not only gives it the desired non-wicking property, but enhances this characteristic by rendering it hydrophobic. The manufacture of such non-woven fabrics is a well developed art. A non-woven fabric can be made to be hydrophilic as well. The functional characteristics desired are sufficient to define and enable the acquisition, from commercial sources, of the fabric employed herein.
The matrix 26 of convoluted filaments may be nylon filaments 28. This is a thermoplastic polyamide resin which may be extruded in situ. The randomly convoluted filament matrix 26 of convoluted filaments is advantageously formed by extrusion of a melted polymer through articulated spinnerets. U.S. Pat. Nos. 3,687,759, 3,691,004 and 4,212, 692, which are incorporated herein by reference, teach methods and apparatus for so forming the matrices of convoluted filaments. U.S. Pat. Nos. 3,687,759, 3,691,004 and 4,212, 692 are incorporated herein by reference in their entirety.
FIGS. 2A-2D are taken from U.S. Pat. No. 4,212,692. At the distance D from the bottom face plate of spinneret 1, a hollow cylindrical roll or drum 2 having a base rim 3 with the profiled projections 4 around its periphery is aligned in such a manner that the four rows of filaments 5 being melt spun from the spinneret 1 are deposited on and between the projections 4 (see FIG. 2C). The deposited filaments 5 form the primary matting sheet M of convoluted filaments, which after cooling is withdrawn from the roll and travels in direction of arrow A to winding take-up or collection means (not shown). The projections 4, may assume the shape of a truncated cone, a truncated pyramid, a hemisphere, a nail or screw with a prominent head, or the like mounted in the surface of the base rim 3 of drum 2. When using a large drum 3, the profiles 4 offer upper peaks 4′ falling in a slightly curved plane so that D fluctuates by a small increment over the four rows of filaments 5. For practical purposes, however, this slightly curved plane provides an approximate horizontal intersection with the vertically falling filaments. The filaments fall on top of each profiled projection and then extend in a random manner into the reentrant or valley portions between the projections in the form of overlapping and intermingled loops, at least some of these loops being directed transversely of the drum as well as longitudinally during the rotation of the drum.
FIG. 2B illustrates an especially preferred profile composed of the truncated pyramids 4. As further shown in FIG. 2C, the continuous looped filaments 5 are deposited on the flattened peaks or upper salient portions 4′ of the truncated pyramids 4 and also in the valleys between truncated pyramids 4 to form the three-dimensional, waffle-shaped matting M. FIG. 2D illustrates the matting M as obtained by spinning filaments onto a profiled surface consisting of projecting hemispheres.
The described matrix 26 of convoluted filaments provides a basic function of spacing the cap shingles 18 above the underlying, peak portion of the compositely formed roof, thus providing a venting passageway for the flow of air from the attic-venting slot 22. Further, this matrix is relatively plastic, i.e., capable of deformation without fracturing. Thus the vent 20 can be nailed, or stapled, to the sub-roofing without the need of special care. That is, while it would be preferable to drive a nail into the sub-roofing so that its head is spaced therefrom a distance approximating the vent thickness, no harm is done if a nail is driven to the point that the matrix is compressed beneath the head.
The described matrix further has a resilient feature which is of particular significance. For example, when installed, the vent 20 is not readily apparent. It must, necessarily, be anticipated that workers on the roof will step on the cap shingles, so that their weight will compress the vent the portion of the matrix 26 beneath their feet. The resilient characteristic of the matrix, after this crushing pressure has been removed, will restore the matrix, substantially, to its original height, thus maintaining the desired venting flow area.
Vent material may be fabricated in indeterminate lengths. The matrix may be formed on and attached to the sheet material layer 24. The sheet material layer is then wrapped around the side edges of the matrix 26 and folded against the upper, marginal surfaces of the matrix and secured thereto by the adhesive layer, FIG. 4. The compositely formed vent material is relatively flexible and may be readily coiled in rolls.
Installation of the vent 20 involves as a first step, a section of venting material may be cut from a roll, with a length approximating, or somewhat greater than, the length of the roof peak to which it is to be applied. The vent 20 is then positioned and positively held in place by a few nails 38, to prevent accidental displacement. The cap shingles 18 are installed, by nails 40, in conventional, overlapping fashion.